Timing device for sheet folding machines



Nov. 4, 1941, F- w. CLEGG ,2

TIMING DEVICE FOR SHEET FOLDING MACHINES Filed June 2]., 1940i 6 Sheds-Sheet I Nov. 4, 1941.

' F. w. CLEGG 2,261,226

TIMING DEVICE FOR SHEET FOLDING MACHINES 2 Filed June 21, 1940 6 Sheets-Sheet 2 Fig.2

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TIMING DEVICE FOR SHEET FOLDING MACHINES v Filed June 21, 1940 6 Sheets-Sheet 3 Fig.3

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TIMING DEVICE FOR SHEET FOLDING MACHINES Filed June 21, 1940 6 Sheets-Sheet 4 Fig.6 Fig.7

NOV. 4,1941. E w LE 2,261,226

TIMING'DEVICE FOR SHEET FOLDING MACHINES Filed June 21, ,1940 s Shets-Sfieet 5 Nov. 4, 1941 F. w. CLEGG 2,261,226

TIMING DEVICE FOR SHEET FOLDING MACHINES Filed June 21, 1940 6 Sheets-Shget 6 Fig.8 41 78 Patented Nov. 4, 1941 TIMING DEVICE'FOR' SHEET FOLDING MACHINES Frederick William Clegg, Peterborough, England, assignor to Baker Perkins Limited, Peterhorough, Northampton, England Application June 21, 1940, Serial No. 341.com. In Great BritainJuly 1,.1939.

15 Claims. (Cl; 270--84)' This invention relates to timing devices for sheet folding mechanism adapted for receiving sheets, tablecloths or likeflatgoods (hereinafter referred to as sheets) from a laundry ironing machine or other source and for folding .the r sheets into half and quarter folds or other desired folding proportions, the timing device-being provided to control the time of the folding operations whereby successive sheets are correctly folded irrespective of varying lengths thereof.

The invention particularly relatesto the type of timing device in which constantly rotating wheels or discs are provided which are adapted respectively to control the folding operation for the half fold and subsequently the quarter fold or other desired folding proportion. In this form of mechanism one wheel or disc is adapted to rotate at a speed conforming to the time taken in travelling from the position at which asheet enters the folding mechanism and the position at which folding occurs. This wheel or disc is referred to hereinafter as the unitary speed wheel. In addition there is a second wheel referred to hereinafter as the half speed or proportional wheel, which rotates at half the speed of the unitary wheel. Associated with the two Wheels is an arm or lever adapted to-be clutched first to the half speed and subsequently to the unitary speed wheel, and to be rotated thereby from zero or -starting position toa position at which means are brought into operation whereby the folding operationsare effected.

As hitherto proposed the clutching of the arm or lever to .either the unitary or half speed wheels was dependent upon friction or of a character such that there was liability to lag or slipso that the timing was inaccurate and folding incorrect.

An object of the present invention is to provide improved means for clutching the arm to the unitary and half speed or proportional wheels whereby la is prevented and thus the sheet is accurately folded.

The invention consists in a timing device of the type described comprising unitary and half speed wheels and a control lever or arm adapted to be clutched to either of said wheels, wherein the lever is clutched to the wheels by positively operating means. a

The invention also consists in atiming device for sheet folding mechanism of the type comprising unitary and half speed or proportional wheels, and a control lever or arm adapted to be clutched thereto, wherein means are provided for positively clutching the arm or lever to either of 55 speed of the feeding tapes of the folding mechasaid wheels while permitting the arm to overrunthe. half speed or proportional wheel when the arm isclutched to the unitary speed wheel.

The .invention alsoconsists in a timing device, as referred to in the preceding paragraph, wherein an additional wheel. or disc is provided adapted to rotate at one quarter the unitary speed andwherein an arm or lever is provided adapted to be positively clutchedto the unitary speed or to the quarter speedwheel, such arm controlling the operation of the folding mechae nism to fold the sheet into quarter f0lds.

According to the preferred form the clutchin meansv comprises ratchet wheels. associated with the unitary and proportional speedwheels or discs and rotatable. therewith, and pawls carried by the arms, or levers and: adapted for engagement in the ratchet wheelsunder the control of means actuated by the leading and trailing edges of a. sheet.

The pawls may beprovided with lateral projections adapted for engagement by laterally. displaceable arcuate stops whereby the pawlsmay be released for engagementwith the appropriate ratchet wheel.

In the accompanying; drawings which illustrate the improved. timing device as arranged for controlling quarter foldin of sheets or other flat. g00ds- Figure 1 is a sectional elevation.

Figure2 is an end view looking from. the right in Figure 1.

Figure 3is a sectional elevation in line 3.--.3 of Figure 1.

Figure 4 is an outside elevation.

Figure 5 is a plan. s

Figures 6 and 7 are views of the control switch and tape guide for the sheets. t

Figure 8 is a diagrammatic plan on line 8-8 of Figure 1 showing the relative position of the arcuate stops and fixed tracks in 'the zero posiion.

Figure 9 is a diagrammatic plan. on line 9-9 of Figure 1 showing the relative position of the arms and the .abutments in the zero position.

In carrying the invention into effect according to one convenient mode as applied to a machine for the folding of sheets into quarter folds, as for example as described in concurrent application No. 341,599 the timing device comprises three wheels or discs H H, [2 mounted freely upon a fixed spindle l3. The wheels are constantly rotated by any suitable mechanism at speeds which conform or are proportional to the nism. Conveniently, the wheels III, II and I2 are provided with gear teeth |4, l5 and I6 driven by pinions l1, I8 and IS on shaft 20 through intermediate gears H1, H8, H9. The shaft 28 is driven from a constantly rotating shaft 2| through the gear 22, the shaft 2| being driven by a chain wheel 23 from a convenient part of the machine.

The centre wheel H which may be referred to as the unitary speed wheel is driven at a speed such that a point thereon in travelling 180 conforms to the time taken by the leading edge of a sheet passing the switch 59 where it enters the folding mechanism to the time at which such edge reaches the folding position. Instead of 180 any other suitable angle may be adopted.

Th other wheels I0 and I2 are mounted on either side of the unitary speed wheel H and one of them I!) is driven at half speed while the other I2 is driven at quarter speed. a The unitary speed wheel H is provided with a rim upon which rings 24 and 25 are provided having ratchet teeth 26, 21. The half speed and quarter speed wheels l0 and I2 also have rims which extend toward the unitary speed wheel and these rims also carry rings 28 and 23 having ratchet teeth 30, 3|.

A space is provided between the rims of the half speed and unitary speed wheels II), II and these spaces accommodates levers or arms 32 which are freely mounted upon the spindle I3 and extend through the space. Conveniently there may be five levers 32 which are cranked so that their outer ends which extend through the space are all brought to the same plane so that the arms lie in a following order.

Similar arms or levers are provided to lie in a space between the unitary speed wheel H and the quarter speed wheel l2.

Considering now the arms 32 associated with the half speed and unitary speed wheels l0 and H, each arm is provided with a pair of spring pressed pawls 33, 34 arranged on either side thereof which pawls are adapted for engagement in the corresponding ratchet wheels 26 and 3|] on the unitary and half speed wheels.

The direction of the ratchet teeth and the arrangement of the pawls is such that when a pawl is in engagement with the ratchet the arm will be driven at the speed of rotation of the corresponding wheel. The arms 32 are adapted to hang normally substantially vertically when in the zero position, the first arm in the series then abuts against a movable abutment 35 while the following arms will abut against each other and take up corresponding positions.

A second abutment 36 is provided which is adapted to be moved into the path of the second arm in the position of rest to prevent this arm moving when the abutment 35 is moved to release the first arm. On the return movement of the abutment 35 the second arm is released from the abutment 36 and moves into the zero position against the abutment 35.

The pawls 33, 34 are provided with lateral projections 31, 38 respectively adapted for engagement by laterally displaceable arcuate stops 40 or 4| and when the stops are moved laterally to release the corresponding pawl such engages with its ratchet wheel under the action of springs 42 whereby the arm is driven.

The arcuate stops 40 and 4| are carried by a common mounting 43 and thus each stop is displaced when the mounting is moved laterally. In order to avoid inappropriate release of the pawls by such movements fixed arcuate tracks 11 and 18 are provided which are located to prevent freeing of the projections 31 and 38 until the arcuate stops in the appropriate control position.

As will be seen from Figure 8 which shows an arm 32 in the zero position the fixed arcuate track 18 extends to a position so that the projection 38 rides onto the half speed arcuate stop 4| which is located in the zero position while the fixed arcuate track 18 extends into the zero position and controls the pawl 33 while the arm 32 is in the zero position.

The lateral projection 38 of the pawl 34 is adapted when the arm 32 is in the zero position to lie against the displaceable arcuate stop 4| whereby the pawl is retained out of engagement with the ratchet teeth 30.

When in the normal position as shown, the displaceable arcuate stop 4| forms a continuation of the fixed arcuate track 18 so that as the arm 32 moves freely to zero position the pawl 34 is held in its retracted position and the projection slides from the track 18 onto the arcuate stop 4|.

The lateral projection 31 of pawl 33 is adapted to be controlled by the fixed track 11 when the arm is in the zero position so that the pawl is prevented from engagement with the ratchet teeth 26. This control by the fixed track is necessary as the normal lateral position of the arcuate stop 48 is such that it would not engage the projection 31.

The arcuate stop 40 is adapted when laterally displaced to be brought in alignment with and form a continuation of the fixed track which occurs when the arcuate stop 4| releases the pawl 34. The projection 31 will then ride off the track 11 and onto the arcuate stop 40.

The release of pawl 33 will occur when the mounting 43 returns to its normal position, the arm 32 having in the meantime been carried round by the action of the pawl 34.

The arcuate stop 40 which controls the pawl associated with the unitary speed wheel H extends from the zero position for about or other suitable angle. The arcuate stop 4| associated with the half speed wheel I0 is a short stop located in or adjacent the zero position as the control and release of the half speed pawl 34 is limited to the locality of the starting position. Thus when the arcuate stop 4| is displaced an immediate release of the pawl 34 to engage the ratchet wheel 30 of the half speed wheel is obtained as already explained.

A similar displaceable mounting 44 having arcuate stops is provided for controlling the pawls on arms located between the unitary and quarter speed wheels. Fixed tracks 11 an 18 are also provided for the unitary and quarter speed mechanism, it being appreciated that a single track 11 is provided both edges of which are utilised.

The mountings 43 and 44 also carry the abut ments 35 and'36.

The mountings 43 and 44 are carried upon rods 45 and 46 respectively, which are supported to slide in apertures in side plates 41 and 48. Return springs 49, 50 are provided between the plates 41 and 48 and the appropriate mountmg.

Movement of the mountings is effected by levers 5| and 52 carried by rock shafts 53 and 54. The levers 5|, 52 are provided with pins 55 abutting against the ends of the rods 45, 46.

The rock shafts 53, 54 are coupled together by levers 55, 51 connected by an adjustable link 58.

The displacement of the mountings 43, 44 is effected by electro-mechanical means which are controlled by a switch 59 actuated by the sheet to be folded. The switch 59 is located at the position where the sheet enters the tapes 50, Si by which it is conveyed to the folding position. The switch 53-is in circuit with a solenoid 62 the core 53 of which is connected to or bears upon a pivoted arm 54. The arm 34 overlies a spring pawl 65 carried by, a pivoted lever 55 which is coupled by a rod 61 to an arm 58 on the rock shaft 53. The pawl 65 cooperates with a ratchet wheel 69 which is rotated by a slip friction drive comprising a pair of friction discs located on either side of the wheel 59 and constantly driven by the shaft 2! to which they are splined. A spring H provides the necessary pressure for the frictional drive.

The arrangement is such that the pawl 65 is in the raised position out of engagement with the ratchet wheel so that the latter rotates idly by the friction drive. Upon actuation of the switch 59 by the entry of a sheet between the tapes 6!), 6| the solenoid 62 is energised and the arm 64 lowered causing engagement of the pawl 55 with the ratchet wheel. The lever 53 is thus angularly displaced about its axis and exerts a pull on the link 61 to rock the shafts 53 and 54. While the solenoid remains energised the lever 65 will be maintained in its displaced position owing to the continued rotation of the friction discs which will constantly urge the ratchet wheel 59 in the appropriate direction.

When the trailing edge of the sheet leaves the switch and the solenoid is de-energised, the pawl 55 will be removed from the ratchet wheel by its spring 12 and the lever 56 returned to its normal position by the spring 13.

The engagement of the pawl 55 with the arm 54 is by means of a roller 14 carried by the pawl engaging a curved surface 15 on the arm.

It will be noted that the unitary wheel is common to the half speed and quarter speed wheels and is located between such, and it is for this reason that the arcuate stops 43, 41 associated with the unitary and half speed ratchets and move in opposite direction to the arcuate stops 40, 4| associated with the unitary and quarter speed ratchets 21 and 3!.

In operation, the parts being in the position indicated in Figure 8 the lateral movement of the mounting 43 and the stop 45 to disengage the projection 38 and release the pawl 34 of the lever or arm 32 located in the zero position so that the pawl will engage the ratchet 30 of the half speed wheel, is effected by the solenoid controlled pawl 55, when a sheet enters the folder feeding tapes and the leading edge actuates the control switch 59. This lateral movement of the mounting 43 also removes the zero abutment 35 so that the arm 32 may commence its rotation by reason of the engagement of pawl 34 with wheel 30. At the same time the second abutment 36 moves into the path of the succeeding arm 32 to prevent this moving to the zero position, this being necessary to prevent the pawl 34 of the succeeding arm also being released, it being appreciated that the track 78 terminates short of the zero position. The movement of the mounting also brings the arcuate stop into position for receiving the projection 31.

Upon such release of the half speed pawl 34 the'arm or lever 32 is clutched to the half speed wheel and is thusrotated atthe speed of such wheel. 1 I The projection 31 of the unitary speed pawl 33 will now be riding upon the arcuate stop 40.

At 'apred'etermined time, depending upon the length of the sheet, and by the trailing edge of the sheet passing the control switch 59 the solen oidi controlled pawl 55 is released and the mounting 43 returned by its springs 49 whereby the arcuate stops 40 and 4| are again laterally displaced. By this movement'of the mounting the arcuate stop 40 is disengaged from the projection 31 and releases the unitary speed pawl 33 which engages the unitary speed ratchet wheel 25. On this occurring the arm 32 will be carried round at unitary speed instead of half speed, the pawl 34 associated with the half speed over running the slower moving half speed wheel.

During the change over from the half speed to unitary speed it will be appreciated that the half speed pawl 34 will still be in engagement with its ratchet wheel 30 so that the arm 32 will be in positive driving engagement with either the half or unitary speed wheel during its actuation and at no time during this period will it be uncontrolled, sothat the arm has no free period; the folding action depending upon the length of the sheet will then be accurately and definitely determined.

The arm 32 continues to move at the unitary speed until it reaches a predetermined position (which is preferably from the zero' position) where it is adapted to actuate a trip lever 16 associated with suitable means for causing or controlling the operation of the half fold means.

The trip lever 16 may be adjustably mounted so. that initial setting adjustments may be made;

When the mounting 43 returned to its initial position to release the unitary pawl 33 on the arm 32, it will be'noted that the arms which were being held by the abutment 35' will be released so as to move on one step toward the zero position in which the short half speed arcuate stops 4| will now be in position in alignment with the fixed track 11 to engage the appropriatepawl projection 38. I

In the meantime similar operations have been effected with regard to an arm located between the unitary speed wheel H and the quarter speed wheel [2 whereby the pawl associated with the quarter speed is first engaged with its ratchet wheel and the arm thereby driven at quarter speed. This engagement, it will be appreciated,

takes place by the lateral displacement of the stop mounting 44 at the same time as the half speed pawl is moved into engagement with its ratchet wheel. The arm moves at the quarter speed until a predetermined point when the arcuate stop associated therewith is moved to release the unitary speed pawl, with the result that the arm associated with the quarter fold which is now angularly displaced from the arm associated with the half fold moves round at unitary speed, and at a predetermined time after the half fold, arm has tripped its mechanism, the quarter fold arm will also trip the mechanism associated with the quarter folding means. After the tripping operations have been effected, the arms 32 continue in their movement by being driven by the unitary speed wheel and the projections 31, 38 on the various pawls 33, 34 are adapted to come into engagement with fixed cam surfaces which conveniently comprise the upper ends of the fixed tracks 11 and 18 whereby they are all drawn out from their re-' spective ratchet wheels so that the arms will then fall by gravity and abut against the end arm of the respective series. I

The fixed tracks 11 and 18 with their cam surfaces are carried by brackets 19 and for the greater part conform to the curvature of the arcuate stops 4!] and 4|.

When folding relatively short articles it will be appreciated that a number of levers or arms will be brought into operation and will simultaneously be travelling toward the trip release position depending upon the number of articles lying between the control switch and the folding position.

Although the preferred form of the invention incorporates clutch means of the ratchet and pawl type, other known forms of positive clutch means may be utilised.

While the invention has been particularly described in connection with the folding of sheets into quarters it may be employed for other folding proportions.

For example, for folding articles in halves only one arm or set of arms 32 operating in conjunction with the half speed and unitary wheels would be utilised.

Articles could be folded in other proportions by simply altering the gear ratios between the unitary speed wheel and the fractional speed wheels. Thus to fold an article into thirds, the half speed wheel would be geared to run at two thirds the speed of the unitary wheel, while the quarter speed wheel l2 would be geared to run at one third the speed of the unitary wheel.

By the provision of a suitable gear change it would be possible to adapt a single timing apparatus to control folding into halves, thirds, quarters or any other proportions.

I claim:

1. A timing device of the type described comprising rotary unitary and fractional speed wheels and a control arm adapted to be clutched to either of said wheels by independently operable clutch devices and driven thereby, the clutch means being of a positive character so that the control arm is positively driven.

2. A timing device of the type described comprising rotary unitary and proportional wheels, a control arm adapted to be clutched to said wheels by independently operable clutch devices to be rotated thereby, the clutch means being such that when the arm is clutched to the unitary wheel the clutch for the proportional wheel remains in and overruns.

3. A timing device of the type described comprising rotary unitary and proportional wheels, a control arm adapted to be clutched to said wheels by independently operable clutch devices to be rotated thereby, the clutch for the proportional wheel providing a one-way drive whereby it remains in and overruns when the clutch for the unitary wheel is put in.

4. In timing device of the type described comprising rotary unitary and proportional discs provided with ratchet teeth, a control arm having a pair of independently controllable pawls adapted for engagement with the respective ratchet teeth, and means actuated by the leading and trailing edges of the article to be folded for controlling said engagement.

5. A timing device of the type described comprising rotary unitary and proportional discs provided with ratchet teeth, a control arm having a pair of independently controllable pawls adapted for engagement with the respective ratchet teeth, lateral projections on said pawls, laterally displaceable arcuate stops co-operating with said projections to control said pawls, said arcuate stops being operated by means actuated by the leading and trailingedges of the article to be folded.

6. A timing device of the type described comprising a rotary unitary speed disc mounted between rotary half speed and quarter speed discs respectively, said discs having ratchet teeth, rotatably mounted control arms located between the unitary and half speed discs and between the unitary and quarter speed discs, each arm having a pair of independently controllable pawls adapted for engagement with the respective ratchet teeth, lateral projections on the pawls, laterally displaceable arcuate stops adapted for engagement with said projections to control the pawls, said arcuate stops being operated by means actuated by the leading and trailing edges of the article to be folded.

'7. A timing device as claimed in claim 6, wherein the arcuate stops associated with the unitary disc extend for about from a zero or starting position to a position where the control arms are adapted to engage a trip lever controlling the folding mechanism, and the arcuate stops associated with the half and quarter speed wheels are limited to the zero position.

8. A timing device as claimed in claim 6, wherein the arcuate stops associated with the unitary disc extend for about 180 from a zero or starting position to a position where the control arms are adapted to engage a trip lever controlling the folding mechanism, and the arcuate stops associated with the half and quarter speed wheels are limited to the zero position and wherein fixed arcuate tracks adapted to engage the pawl projections and having cam portions for releasing the pawls from the respective ratchet teeth extend from the tripping position to the Zero position.

9. A timing device as claimed in claim 6, wherein the arcuate stops associated with the unitary disc extend for about 180 from a zero or starting position to a position where the control arms are adapted to engage a trip lever controlling the folding mechanism, and the arcuate stops associated with the half and quarter speed Wheels are limited to the Zero position and wherein fixed arcuate tracks adapted to engage the pawl projections and having cam portions for releasing the pawls from the respective ratchet teeth extend from the tripping position to the zero position, the fixed track associated with the unitary pawls extending into the zero position and controlling the unitary pawls in said position.

10. A timing device as claimed in claim 6, wherein the arcuate stops are carried upon a pair of curved mountings supported upon axially displaceable rods arranged parallel to the rotary axis of the wheels.

11. A timing device as claimed in claim 6, wherein the arcuate stops are carried upon a pair of curved mountings supported upon axially displaceable rods arranged parallel to the rotary axis of the wheels, said rods moving against the action of returning springs to release the pawls associated with the half and quarter speed wheels by lever arms carried by a pair of rock shafts which are linked together so that the mountings move in opposite directions.

12. A timing device as claimed in claim 6, wherein the arcuate stops are carried upon a pair of curved mountings supported upon axially displaceable rods arranged parallel to the rotary axis of the wheels, said rods moving against the action of returning springs to release the pawls associated with the half and quarter speed wheels by lever arms carried by a pair of rock shafts which are linked together so that the mountings move in opposite directions, said rock shafts being oscillated by solenoid actuated means under the control of a switch operated by the leading and trailing edges of the article to be folded.

13. A timing device as claimed in claim 6, wherein the arcuate stops are carried upon a pair of curved mountings supported upon axially displaceable rods arranged parallel to the rotary axis of the wheels, said rods moving against the action of returning springs to release the pawls associated with the half and quarter speed wheels by lever arms carried by a pair of rock shafts which are linked together so that the mountings move in opposite directions, said rock shafts being oscillated by a pawl lever coupled to the rock shafts, the pawl co-operating with a ratchet wheel rotated by a slip friction device.

14. A timing device as claimed in claim 6, wherein a. plurality of control arms arranged in serial order is provided for the half fold means and a similar plurality of control arms is provided for the quarter fold means and laterally displaceable abutments for engaging and controlling the first and second arms in the series as they move to a zero or starting position.

15. A timing device as claimed in claim 6, wherein a plurality of control arms arranged in serial order is provided for the half fold means and a similar plurality of control arms is provided for the quarter foldmeans and laterally displaceable abutments for engaging and controlling the first and second arms in the series as they move to a zero or starting position, said abutments being carried by curved mountings which also carry the arcuate stops and means for laterally displacing the mountings.

FREDERICK WILLIAM CLEGG. 

